Fc variants with increased affinity for FcγRIIc

Abstract

The present invention relates to Fc variants having increased affinity for FcγRIIc, methods for their generation, Fc polypeptides comprising optimized Fc variants, and methods for using optimized Fc variants.

We claim: 
     
       1. A nucleic acid encoding a protein comprising an Fc variant of a parent Fc polypeptide, wherein the Fc variant comprises amino acid substitutions 239D, 332E and 330L, and numbering is according to the EU index. 
     
     
       2. The nucleic acid of  claim 1 , wherein the parent Fc polypeptide is human IgG1. 
     
     
       3. The nucleic acid of  claim 1 , wherein the protein is an antibody. 
     
     
       4. The nucleic acid of  claim 3 , wherein the antibody is selected from the group consisting of a human antibody, a humanized antibody, and a chimeric antibody. 
     
     
       5. The nucleic acid of  claim 1 , wherein the protein is an Fc fusion protein. 
     
     
       6. An expression vector comprising the nucleic acid of  claim 1 . 
     
     
       7. A host cell comprising the nucleic acid of  claim 1 . 
     
     
       8. A host cell comprising the expression vector of  claim 6 . 
     
     
       9. A method of making a protein comprising: a) culturing the host cell of  claim 7  under conditions wherein the protein is expressed; and b) recovering the protein. 
     
     
       10. A method of making a protein comprising: a) culturing the host cell of  claim 8  under conditions wherein the protein is expressed; and b) recovering the protein.